Hair cutting machine

ABSTRACT

A HAIR CUTTING MACHINE WITH AT LEAST ONE CUTTING BLADE BETWEEN TWO PLATES HAVING ROWS OF TEETH IN PARALLEL WITH THE CUTTING EDGE OF THE BLADE. THE PLATE COMPRISE FLAT OR SLIGHTLY CONCAVE GUIDE SURFACES HAVING DIFFERENT PERPENDICULAR DISTANCE FROM THE CUTTING EDGE. PREVIOUS HAIR CUTTING MACHINES WITH INTERCHANGEABLE BLADES SUPPORTED BETWEEN TWO PLATES COMPRISE BASE PLATES HAVING DOUBLE COMBS WITH A HANDLE DESIGNED TO SUPPORT THESE BLADES. COVER PLATES ARE ATTACHED TO THE BASE PLATES AND THE BLADES ARE HELD BETWEEN BOTH. BOTH BASE PLATE AND COVER PLATE HAVE ROWS OF TEETH RUNNING PARALLEL WITH THE CUTTING EDGES OF THE BLADES. THE OUTER SURFACES OF THE PLATES HAVE CONVEX CURVATURE NORMAL TO THE CUTTING EDGES OF THE BLADES, THIS CONVEX CURVATURE PASSES OVER TO THE CURVATURE OF THE EXTERNAL EDGES OF THE TEETH. THIS TYPE OF HAIR CLIPPER HAS ALSO BEEN DESIGNED WITH ONE OF ITS SIDES FORMING A CUTTING COMB AND THE OTHER A NORMAL COMB. WITH THIS TYPE OF HAIR CLIPPER IT IS POSSIBLE TO CHANGE THE CUTTING LENGTH OF THE HAIR, BUT THERE IS NO POSSIBILITY TO MAKE EXACT ADJUSTMENTS BECAUSE THE SETTING ANGLE OF THE MACHINE CANNOT EXACTLY BE DETERMINED ON ITS HEAD. NEW TYPES OF HAIR CUTTING MACHINES, EQUIPPED WITH RAZOR BLADES WHICH ARE HELD BETWEEN PLATES, PERMIT A CONSIDERABLE IMPROVEMENT IN GRADUATION OF CUTTING STAGES WITHOUT MECHANICAL ALTERATIONS OF THE MACHINE. THIS IS DUE TO THE FACT THAT BOTH PLATES HAVE ALMOST THE SAME SIZE, THAT EACH SIDE OF THE TWO PLATES PARALLEL WITH THE CUTTING EDGES OF THE BLADES HAS A ROW OF TEETH, AND THAT THE LENGTH OF THE TEETH OF ONE ROW IS DIFFERENT FROM THAT OF THE TEETH BELONGING TO THE OTHER ROW. THIS TYPE OF MACHINE, HAVING TWO CUTTING COMBS WITH TEETH OF DIFFERENT LENGTH OF BOTH SIDES OF THE CUTTING EDGE, ALLOWS OPERATING IN FOUR DIFFERENT CUTTING STAGES. THIS IS DUE TO THE DIFFERENT LENGTH OF TEETH, AND THE FACT THAT, AS A RESULT OF THE SYMMETRICAL DESIGN OF BOTH BASE AND COVER PLATE, THE MACHINE CAN BE USED IN EVERY CUTTING POSITION. HAIR CUTTING MACHINES OF THIS TYPE HAVE ALSO BEEN USED IN VERSIONS HAVING MORE THAN TWO CUTTING COMBS, I.E., MORE THAN TWO OPERATIVE CUTTING EDGES OF THE BLADES. THE CUTTING LENGTH OF THE HAIR, OBTAINED WITH THIS TYPE OF HAIR CUTTING MACHINE, DEPENDS ON THE DISTANCE IN WHICH THE CUTTING EDGE OF THE BLADE IS PASSED THROUGH THE HAIR ABOVE THE SKIN OF THE HEAD. MOREOVER, THE THINNING-OUT EFFECT DEPENDS ON THE CUTTING ANGLE, I.E., THE ANGLE FORMED BY THE DIRECTION OF THE GUIDE MOTION OF THE BLADE AND THE PLANE OF THE BLADE. THE HAIR CUTTING AND THINNING-OUT INSTRUMENTS DESCRIBED ABOVE HAVE TEETH, THE EXTERNAL EDGES OF WHICH MORE OR LESS HAVE CONVEX CURVATURE, MAKING IT POSSIBLE TO CHANGE TO A CERTAIN EXTENT THE LENGTH OF THE HAIR-CUT BY VARYING THE CUTTING ANGLE. THESE CONTINUOUS GRADUATIONS IN A HAIR-CUT&#39;&#39;S LENGTH, HOWEVER, CANNOT EXACTLY BE DETERMINED DURING THE CUTTING OPERATION, THUS REQUIRING CONSIDERABLE SKILL TO MAKE POSSIBLE A PERFECT HAIRCUT WHEN USING THESE GENERALLY KNOWN MACHINES. IN PARTICULAR, IT IS DIFFICULT TO CARRY OUT A CORRECT TRANSITION CUT FROM THE BACK-HAIR TO THE HAIR OF THE HEAD. OTHER HAIR CUTTING MACHINES HAVE INTERCHANGEABLE BLADES SUPPORTED BETWEEN TWO PLATES, ONE OF WHICH HAS A ROW OF TEETH ON THE SIDE THAT RUNS PARALLEL WITH ONE CUTING EDGE OF THE BLADE, THE CUTTING EDGE ITSELF BEING OVERLAPED BY THE TEETH. THE EXTERNAL EDGES OF THESE TEETH LIE PARTIALLY OR TOTALLY IN A GUIDE SURFACE WHICH RUNS PARALLEL, PLAIN OR IN A SLIGHT CONVEX CURVATURE WITH THE CORRESPONDING CUTTING EDGE. THE GUIDE SURFACE SETS OFF CLEARLY AGAINST THE REST OF THE MACHINE&#39;&#39;S SURFACE. FOR ADJUSTMENT OF THE CUTTING LENGTH IN THIS TYPE OF GENERALLY KNOWN HAIR CUTTING MACHINE, THE BLADE IN ANY CASE MUST BE DISPLACED AGAINST THE TEETH, THUS COMPLICATING HAIR CUTTING TO SUCH AN EXTENT THAT IT BECOMES IMPOSSIBLE FOR AN AMATEUR TO CUT HIS OWN HAIR WITH GOOD RESULTS.

' Oct. 19, 1971 w, GUMBMANN b 3,613,234

HAIR CUTTING MACHINE Filed May 2, 1969 3 Sheets-Sheet 1 8 rd re r114 10 H6. 2

364246 3627 Z! 22 4&5 4/

Oct. 19, 1971 w, GUMBMANN 3,613,234

HAIR CUTTING MACHINE Filed May a, 1969 3 Sheets-Sheet 3 W. GUMBMANN HAIR CUTTING MACHINE Oct 19, 1971 s Sheets-Sheet 5 Filed May a. 1969 FIGQ8 FIG. 9

FIG. 12

FIG. 11

United States Patent 3,613,234 HAIR CUTTING MACHINE Wilhelm Gumbmann, Herbsthalde,

7 Stuttgart 1, Germany Filed May 2, 1969, Ser. No. 821,315 Claims priority, application Austria, May 10, 1968, A 4,529/68; Dec. 2, 1968, P 18 12 214.0 Int. Cl. B261) 21/12 U.S. Cl. -31 7 Claims ABSTRACT OF THE DISCLOSURE A hair cutting machine with at least one cutting blade between two plates having rows of teeth in parallel with the cutting edge of the blade. The plates comprise fiat or slightly concave guide surfaces having different perpendicular distances from the cutting edge.

Previous hair cutting machines with interchangeable blades supported between two plates comprise base plates having double combs with a handle designed to support these blades. Cover plates are attached to the base plates and the blades are held between both. Both base plate and cover plate have rows of teeth running parallel with the cutting edges of the blades. The outer surfaces of the plates have convex curvature normal to the cutting edges of the blades; this convex curvature passes over to the curvature of the external edges of the teeth. This type of hair clipper has also been designed with one of its sides forming a cutting comb and the other a normal comb. With this type of hair clipper it is possible to change the cutting length of the hair, but there is no possibility to make exact adjustments because the setting angle of the machine cannot exactly be determined on its head.

New types of hair cutting machines, equipped with razor blades which are held between plates, permit a considerable improvement in graduation of cutting stages without mechanical alterations of the machine. This is due to the fact that both plates have almost the same size, that each side of the two plates parallel With the cutting edges of the blades has a row of teeth, and that the length of the teeth of one row is different from that of the teeth belonging to the other row. This type of machine, having two cutting combs with teeth of different length on both sides of the cutting edge, allows operating in four different cutting stages. This is due to the different length of teeth, and the fact that, as a result of the symmetrical design of both base and cover plate, the machine can be used in every cutting position, Hair cutting machines of this type have also been used in versions having more than two cutting combs, i.e., more than two operative cutting edges of the blades.

The cutting length of the hair, obtained with this type of hair cutting machine, depends on the distance in which the cutting edge of the blade is passed through the hair above the skin of the head. Moreover, the thinning-out effect depends on the cutting angle, i.e., the angle formed by the direction of the guide motion of the blade and the plane of the blade. The hair cutting and thinning-out instruments described above have teeth, the external edges of which more or less have convex curvature, making it possible to change to a certain extent the length of the hair-cut by varying the cutting angle. These continuous graduations in a hair-cuts length, however, cannot exactly be determined during the cutting operation, thus requiring considerable skill to make possible a perfect haircut when using these generally known machines. In particular, it is difiicult to carry out a correct transition cut from the back-hair to the hair of the head.

Other hair cutting machines have interchangeable blades supported between two plates, one of which has a row of teeth on the side that runs parallel With one cutice ting edge of the blade, the cutting edge itself being overlapped by the teeth. The external edges of these teeth lie partially or totally in a guide surface which runs parallel, plain or in a slight convex curvature with the corresponding cutting edge. The guide surface sets off clearly against the rest of the machines surface. For adjustment of the cutting length in this type of generally known hair cutting machine, the blade in any case must be displaced against the teeth, thus complicating hair cutting to such an extent that it becomes impossible for an amateur to cut his own hair with good results.

SUMMARY OF THE INVENTION The present invention is directed to the problem of creating a hair cutting machine that permits successive cutting in several cutting stages without any adjustments,

the number of cutting stages being twice the number of operative cutting edges of the blades. The user of this machine should be able to adjust without much skill the cutting stages in accordance with the exact cutting length of the hair.

The present invention provides a hair cutting machine wherein the perpendicular distances between various guide surfaces and a predetermined cutting edge are different. In this machine, a guide surface is coordinated to each cutting stage. This guide surface is defined by the exterior edges of the teeth and can be evenly adapted to the skin of the head. The guide surface does not pass over continuously to the adjacent surfaces of the teeth or of the plates, so that correct adapting of the guide surfaces to the skin of the head can clearly be felt. If, for example, a three-blade hair cutting machine is used, i.e., a machine with at least three rows of teeth in parallel with the cutting edges of the blade on the base plate and the cover plate, it is possible to work in at least six cutting stages which can readily be adjusted by adapting the guide surfaces to the skin of the head. All that has to be done when cutting the hair is to adapt the rows of teeth to the skin of the head within the area of the guide surfaces suitable to the cutting stages, and to work in the various zones with corresponding cutting stages. In this way it is possible to achieve perfectly gradated transition cuts at the neck zone.

The guide surfaces of a hair cutting machine of this type, defined by the external edges of the teeth, can form different angles with the plane of the blade, thus enabling the manufacturer of the machine to determine optimum cutting angles for a certain cutting length of the hair.

In another version according to the invention, the external edges of the teeth in one row are divided into several groups resting in different guide surfaces that form an obtuse angle with each other. This permits combinations of the same cutting length with different cutting angles, or different cutting lengths with different cutting angles on one side of a blades cutting edge. This version of the invention permits further improvements in the gradation of cutting stages.

It has been found beneficial, especially in case of long cutting lengths, not to confine the guide surfaces by the plates; but rather to leave a certain distance between the external tooth edges resting in the guide surfaces and the joints of the teeth with the plates. In this way the hair can be cut much easier, since it is not pressed against the skin of the head by the plates.

The invention can be embodied effectively in a hair cutting machine wherein the base and cover plate are symmetrical both to the plane of the blade and to the two planes at right angle to it. This type of machine usually has two parallel cutting edges. In most cases, however, it comprises, according to the invention, at least three cutting edges that can be used without any mechanical variations of the machine. In this case both base and cover plate have either triangular or rectangular shapes. In the case of rectangular shape, one edge may be designed as a normal comb.

Another version of the hair cutting machine according to this invention has only one interchangeable blade between the two plates, one of which Serves as bearer plate for the blade and the other as cover plate. The cover plate can be moved substantially perpendicular to the operative cutting edge of the blade, so that in different positions of the cover plate, relative to the bearer plate, the teeth of the cover plate overlap the blades cutting edge by different distances. Because the external edges of the teeth of the cover plate, looking away from the blade, rest, ac-

cording to the invention, in a plain or slightly convex curved guide surface, it is possible in certain positions of the cover plate relative to the position of the bearer plate to adjust differently defined cutting lengths. This version, too, can be used for each adjustment, i.e., for each position of the cover plate relative to that of the bearer plate, in two different cutting positions, the cover plate or the bearer plate being turned to the skin of the head, according to the cutting position. In the position in which the bearer plate is turned to the skin of the head and the teeth of the cover plate overlap those of the bearer plate, an advantageous stretching of the skin of the head between the tooth tips of both rows of teeth can be achieved so that, especially in case of short cutting lengths, the hair can be cut very accurately. The essential effect of the invention is not due to the fact that the cover plate is displaceable against the bearer plate, but is rather a result of the special design of the teeth both of the cover plate and the bearer plate. It is also due to the fact that both plates have teeth, so that with a few positions of the plates relative to each other, a number of cutting positions for different cutting lengths can be attained. These features result in correct hair-cuts.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described by the way of example with reference to the drawings.

FIG. 1 illustrates the principle of the hair cutting ma chine in accordance with this invention.

FIG. 2 is a section through the cutting comb according to the invention.

FIG. 3 shows a section of a modified version of the cutting comb.

FIG. 4 is a plan view of the inner side of the blade bearer plate in a preferred version of the hair cutting machine in accordance with the invention.

FIG. 5 is a plan view of the inner side of the cover plate of the hair cutting machine.

FIG. 6 shows a section along a line VI-VI in FIGS. 4 and S.

FIG. 7 shows a section along a line VIIVII in FIGS. 4 and 5.

FIG. 8 is a sectional view of another version of the hair cutting machine in accordance with the invention, along a line VI'IIVIII in FIG. 10. This version has a cover plate which can be displaced against the bearer plate of the blade.

FIG. 9 shows the hair cutting machine illustrated in FIG. 8 in another position for the cutting length.

FIG. 10 is a plan view of the hair cutting machine illustrated in FIG. 8.

FIG. 11 is a section along a line XIXI in FIG. 10. FIG. 12 is a section along a line XII-XII in FIG. 10.

DETAILED DESCRIPTION FIG. 1 shows a schematic view of a blade 1 with its cutting edges 2 and 3 in a sectional plane vertical to the plane of the blade. The blade 1 may be supported between two plates which are not shown in FIG. 1. These plates have rows of teeth which run parallel with the 4 cutting edge 2 of the blade, overlapping this cutting edge 2.

In accordance with the invention, the external edges of the teeth of such a row lie partially or entirely in the guide surfaces which run parallel or plain with the corresponding cutting edge 2 or which have a slight convex curvature in direction relative to the cutting edges. FIG. 1 shows diagrammatically the three guide surfaces 4, 5 and 6 situated above the plane of the blade, and the guide surfaces 7, 8 and 9 situated below that plane. These guide surfaces form certain cutting angles with the plane of the blade. The cutting angles of the guide surfaces 4, 5 and 6 are equal, and those of the guide surfaces 7, 8 and 9 are equal; the cutting angles of the upper guide surfaces being different from those of the lower ones. The cutting angle of this hair cutting machine is clearly defined by the corresponding guide surface.

FIG. 1 shows clearly that the perpendicular distances a, b and c on the one side and the perpendicular distances d, e, and f on the other, of the guide surfaces from the cutting edge 2 are different. The different cutting lengths coordinated to corresponding guide surfaces area result of those different distances.

FIG. 2 shows a partial section through a hair cutting device or machine embodying the invention. A head or handle including a bearer plate 10 which has a row of teeth 11 running parallel with the cutting edge 2 of the blade. The external edges of these teeth lie entirely in a plain guide surface 12 which has a vertical distance g from the blades cutting edge 2. By the vertical distance is understood the distance between the cutting edge 2 of the blade and the foot 13 of the vertical projection of this cutting edge on the guide surface 12. The guide surface 12, in which are located the external edges of the teeth 11, at its point 14 passes over discontinuously to the bearer plate 10, i.e., the guide surface 12 is clearly set off from the bearer plate. When adapting the guide surface to the skin of the head, it can clearly be felt if the guide surface is resting evenly on the skin or if the discontinuity point 14 comes into contact with the skin, and this is an essential feature of the invention.

The external edges of the teeth 15 belonging to the cover plate 16, also define partially a guide surface 17, which has a distance h from the cutting edge 2 of the blade. The cutting edge at the side of the cover plate 16 is larger than that at the side of the bearer plate 10. Of course, it is the users choice at which side of the machine he wants to have a smaller or a larger cutting stage. While the external edges of the teeth 11, which are resting within the guide surface 12, join the outer surface of the plate 10 at the discontinuity point 14, the external edges of the teeth 15 lie within the guide surface 17 at a certain distance from the joints of the teeth with the plate 16. Thus, the plate 16 cannot press the hair against the skin of the head. This is another feature of the invention, having importance for longer cutting lengths.

FIG. 3 illustrates a version of the hair cutting machine according to the invention, which is similar to that of FIG. 2. The same reference numbers have been used for identical parts. The version shown in FIG. 3 differs from that illustrated in FIG. 2 only inasmuch as the guide surfaces 17' and 12', defined by the external edges of the teeth 15 and 11, are not plain, but have convex shapes curved in direction towards the cutting edge 2. Since the skin of the head is slightly curved, curved guide surfaces suitable to the mean curvature of the skin of the head can be used. It has been proved, however, that almost the same effect can be obtained using plain guide surfaces.

FIGS. 4 and 5 show plan views of rectangular machines in accordance with the invention, having three cutting combs and one normal comb. The machine has a bearer plate 20 and a cover plate 21. The bearer plate has projections 22 which serve to fix the blades 23, 24

and in the positions shown by the dotted lines. The projections may also be diamond-shaped, round or elongated. Moreover, slotted bars may be used to lock the blades in position. A bow 26 serves for locking together bearer plate and cover plate. The bow 26 is connected with the plate 20 by means of a bar 27 (see FIG. 6).

In another version of the hair cutting machine in accordance with the invention, both cover plate and bearer plate are put together by means of a bolt which is inserted in the bearer plate and passed through the cover plate where a nut is screwed on it to hold both plates together.

The bearer plate has three rows of teeth 28, 29 and 30 of different length. FIGS. 6 and 7 show that the external edges of these teeth define the guide surfaces 31, 32 and 33 which have different distances from the cutting edges 34, 35 and 36. The positions of these cutting edges in the FIGS. 6 and 7 are marked by dots.

The cover plate illustrated in FIG. 5 has four recesses 37 into which the projections 22 shown in FIG. 4 are inserted. The recess 38 serves to hold the bow 26 when the hair cutting machine is put together. The cover plate has four rows of teeth 39, 40, 41 and 42. The external edges of these teeth define the guide surfaces 43, 44 and 45 which have different distances from the corresponding cutting edges. The teeth 39 represent a comb which forms a solid block with the cover plate. FIGS. 6 and 7 illustrate clearly that the distances between the guide surfaces 45, 33, 43, 31, 44 and 42 increase progressively, so that the machine can operate in six defined cutting stages.

The edges of the teeth 30 define, in addition to the guide surface 33, another guide surface 47. Both surfaces form an obtuse angle with each other. The object of the guide surface 47 is to provide or enable a very fine transition cut in the neck zone. In this way, several guide surfaces can be coordinated to each row of teeth, permitting up to 12 different cutting stages.

Another version of a hair cutting machine in accordance with this invention provides cutting combs on all four sides. This version provides defined adjustments of up to 16 different cutting stages.

The version of a hair cutting machine in accordance with the invention illustrated in FIGS. 8 through 12 has a bearer plate 200 with projections 2Z0 holding the blade 1 in the position shown in the drawing. It has a cover plate 21.0 with ledges 211 on both sides sliding in grooves 201 provided in the bearer plate 200. The ledges 211 are fitted firmly in the grooves 201 to enable the cover plate to be displaced against the bearer plate only if a certain amount of force is applied to it, so that the plates cannot get displaced inadvertently during a cutting operation.

The external edges 245 of the teeth 242 with their tapered ends rest in plain guide surfaces parallel with the blades cutting edge 2. The distance of these guide surfaces from the cutting edge of the blade changes when the cover plate 210 is displaced against the bearer plate in the direction of the arrow 215 (FIG. 10).

The edges of the bearer plates teeth 110, looking away from the cutting edge 2 of the blade, also lie in a plain guide surface 120, which in the embodiment illustrated in the drawings practically has no distance from the blades cutting edge 2. In the position shown in FIG. 8, the hair cutting machine, with its bearer plate turned to the skin of the head, can be used to shave off the hair in the neck zone. In this case, too, safe and defined sliding of the machine along the skin of the head will be ensured by the plain surface 120.

In a position in which the cover plate is displaced against the bearer plate in such a way that the teeth 242 project to a larger extent beyond the blades cutting edge 2 than is shown in FIG. 8, the tips 234 of the cover plates teeth 242 take effect also in case the bearer plate is resting against the skin of the head. They stretch the skin of the head, thus raising up the hair between the teeth 242, so that the hair is pushed against the cutting edge 2 of the blade. FIG. 9 embodies a position in which the hair is cut shorter, when the bearer plate 200 is turned to the skin of the head. In the embodiments illustrated in the FIGS. 9 through 12, each position of the cover plate relative to the bearer plate, too, permits two cutting stages.

The cover plate has markings 1 through 6 which can be aligned with the arrows provided on the bearer plate, in order to enable adjustments of defined positions of both plates relative to each other.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A hair cutting device comprising a head, a blade mounted on said head and having a cutting edge spaced therefrom, a first guide comb mounted on said head and on one side of said blade and having outer guide faces extending across said cutting edge, a second guide comb mounted on said head on the other side of said blade and having outer guide faces extending across said cutting edge, said guide surfaces of said first guide comb and said guide surfaces of said second guide comb converging from said head at difierent angles of inclination.

2. A hair cutting device as defined by claim 1 wherein said guide surfaces converge to an apex coplanar with said cutting edge.

3. A hair cutting device as defined by claim 1 wherein the guide surfaces of said first guide comb and the guide surfaces of said second guide comb define an acute angle therebetween.

4. A hair cutting device as defined by claim 1 wherein the guide surfaces of said first guide comb and the guide surfaces of said second guide comb form an obtuse angle therebetween.

5. A hair cutting device as defined by claim 1 where one of said combs being adjustable movable transversely to the cutting edge of said blade.

6. A hair cutting device as defined by claim 1 wherein the angle of inclination of the guide surfaces of at least one of said combs has coplanar portions forming an acute angle with the guide surfaces of the other of said combs and has other coplanar portions forming obtuse angles with the guiding surfaces of said other of said combs.

7. A hair cutting device as defined by claim 6 wherein said other coplanar portions converge with the guide surfaces of said one of said combs to an apex in the plane of said cutting edge.

References Cited UNITED STATES PATENTS 2,141,340 12/1938 Baumgarten 3030 2,512,289 6/1950 Shaeffer 303l 2,514,774 7/1950 Leedy 3030 2,615,244 10/1952 Mansfield 3031 2,718,693 9/1955 Gent 3031 TRAVIS S. MCGEHEE, Primary Examiner 

